Position-free sensor control system of high speed brushless direct current motor

Abstract

A position-free sensor control system of a high speed brushless direct current motor is mainly formed by a digital controller, a full control three phase rectifying bridge, a three phase trebling chopper, a three phase inverter bridge, the high speed brushless direct current motor, a phase current sensor and other parts. Aiming at the problem of large loss of a large-current high-frequency modulating vortex of the high speed brushless direct current motor, the position-free sensor control system disclosed by the invention adopts the full control three phase rectifying bridge and the three phase trebling chopper to perform dual-level electric energy modulating so as to conduct tracking control on the phase current outputted by the three phase inverter bridge. The digital controller adjusts the duty ratio of nine paths of PWM (pulse-width modulation) modulating signals according to tracking error of the phase current, and compensates six paths of phase changing logic signals in real time, thus realizing the high speed rotating of the high-speed brushless direct motor under low vortex loss. The position-free sensor control system of the high speed brushless direct current motor effectivley solves the problem of large vortex loss during the high-speed rotatation of the high speed brushless direct current motor and has important applying value in the control and research of the position-free sensor of the high-speed brushless direct current motor.

Description

technical field [0001] The invention relates to a high-speed brushless DC motor control system, especially a low eddy current loss control system using a position sensorless control mode, which can be used as a high-power motor for high-power high-speed equipment such as refrigeration compressors, natural gas pipeline compressors, and aerators. A control system. Background technique [0002] High-speed brushless DC motors for high-speed equipment such as refrigeration compressors, natural gas pipeline compressors, and aerators usually feature small armature inductance. Brushless DC motors with small armature inductance are prone to the problems of rich high-order harmonics of armature current and large eddy current losses in high-speed rotation. [0003] At present, the power of high-speed brushless DC motors used in compressors and aerators can reach 100kW (32000r / min), or even 315kW (20000r / min). The control systems of high-speed brushless DC motors represented by patent...

AI Technical Summary

Problems solved by technology

[0005] The technical problem solved by the present invention is: to solve the problem of high harmonic content of the phase current when the existing high-speed brushless DC motor rotates at high speed; to propose a position sensorless control system for the high-speed brushless DC motor, which has the motor high-speed The advantages of correct commutation logic during rotation, low harmonic content of phase current, and low eddy current loss

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